Answer:
? = 14
Step-by-step explanation:
If ∆EFG ~ ∆CBA, we have the proportion
FG/FE = BA/BC . . . . . any pairs of corresponding sides will have the same ratio for similar triangles. (It is convenient to put the unknown in the numerator.)
?/18 = 21/27 . . . . . . filling in the given numbers
Multiplying by 18, we have ...
? = 18·21/27
? = 14
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If the triangles are not designated as being similar, the problem is unworkable.
